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It’s week six and your little sweet pea is the size of…a sweet pea. Still tadpole (or prawn) shaped, that baby shrimp won’t be a shrimp much longer…in fact, he or she is growing quickly, measuring one-sixth of an inch from crown to rump this week.

Why do we measure from head to tail? Right now, your baby’s body is curved over into a C-shape, and eventually, when those tiny legs start to form, your little one’s knees will be bent and tucked up under the chin. And that makes it tough to measure the head to toe length of the body. Instead, doctors measure from cute crown to just-as-cute rump until baby hits the 27-week mark, when a head-to-toe measurement takes over.

Incredibly, your baby is starting to gain those features that hint at the adorable little one to come — you know, human stuff like a head and the beginnings of the facial features you’ll soon cover with kisses — the mouth, eyes, jaw, and chin. See those little indentations where you think those pinchable cheeks will be? Nope, those aren't dimples — they’re ear buds.

Talking about budding buds, check out the limb buds that are starting to sprout from the trunk. They’ll grow into arms and legs. And very soon, nodules will develop at the ends of these limb buds and eventually become small hands and tiny feet.

And that’s just what’s happening on the outside. There’s plenty of activity on the inside as well. Major organs are taking shape, including the kidneys, liver, and lungs. And that brand new heart is already beating an impressive 80 to 100 times per minute, a rate that’s rising every day.

Fueling all this growth is the yolk sac — a balloon-like structure attached to the embryo. But the early placenta — known as the chorionic villi — has started to develop and form blood vessels, gearing up to take over and bring nutrition to the fetus when the yolk sac disappears by the end of the first trimester.